The overall goal of the NGEC is the application of genome engineering to hematopoietic stem cells for the purpose of gene repair. Achieving this goal will require work among the seven NGEC scientific components to be tightly integrated. A secondary aim of the NGEC is to promote the development of genome engineering as a scientific discipline. This T90/R90 component will function to promote both of these objectives by supporting interdisciplinary training of post-doctoral level individuals in genome engineeringrelated fields. f Selected individuals will carry out projects spanning two or more disciplines with co-mentoring by two principal investigators with complementary expertise. Support is requested for one position in year one, three positions in year 2, and four positions in years 3-5. Fellows will be chosen on the basis of the interdisciplinary nature of their project and its relationship to genome engineering. The period of training will be up to two years, and training will involve active research and associated laboratory meetings, NGEC group meetings (see component 1), presentation of their data at the annual Workshop for Genome Engineering (see component 9), and travel to an outside meeting each year. Options are also provided for additional interdisciplinary experiences including didactic coursework, a biotechnology externship, the many interdisciplinary symposia and workshops which take place among NGEC institutions, and graduate level teaching.